1. Field of the Invention
This invention relates to an engine automatic start stop control apparatus that automatically stops an idling engine in accordance with prescribed conditions.
This application is based on Japanese Patent Application No.11-230131, the contents of which are incorporated herein by reference.
2. Description of the Related Art
Recently, environmental problems such as global warming have become the focus of attention, and electric cars and hybrid vehicles have been actively developed so as to reduce the discharge of carbon dioxide and the like. Electric cars have no exhaust gas discharge; thus, they are most preferable in consideration of the environmental problems. However, the cruising range per single charge is short; thus, it is necessary to examine the practical possibility of vehicles employing an engine.
Hybrid vehicles comprise an engine and an (electric) motor, wherein the battery is charged using the rotation of the engine. When the discharge of carbon dioxide or the like is relatively large and the engine (rotation) speed is low, it is possible to drive the vehicle by only using the motor or by using both the engine and motor, thereby decreasing the discharge of carbon dioxide. Recently, hybrid vehicles have found practical use because the discharge of the carbon dioxide can be reduced and long distance driving is possible while the characteristics specific to conventional vehicles (i.e., cruising range, operability, and the like) can be maintained.
A technique for automatically stopping the engine has recently become the focus of attention, where the objective of this technique is to reduce the discharge of carbon dioxide and NOx by automatically stopping the engine during idling and by subsequently automatically starting the engine.
For example, when using a gear other than the first gear, when a clutch pedal is depressed, and when the vehicle speed is below a predetermined speed, it can be determined that the driver would like to stop the vehicle, and then the engine is automatically stopped. However, in this situation, the driver may not intend to stop the vehicle. In this case, when the driver releases the clutch pedal to accelerate the vehicle and depresses the accelerator pedal, the vehicle cannot accelerates as the driver wants to, and the drivability may be degraded.
It is therefore an object of the present invention to provide an engine automatic start stop control apparatus which can control the engine and which controls the idling operation to reduce exhaust gas while maintaining the drivability.
The engine automatic start stop control apparatus of the present invention that controls an engine to automatically stop or start in response to the driving conditions of a vehicle, comprises: a clutch detector (SB18) for detecting depression of a clutch pedal; an accelerator detector (SB26) for detecting depression of an accelerator pedal; an automatic stop detector (18, SB10) for detecting an automatic stop of the engine; a stop history checker (18, SB24) for checking the history of the stops of the vehicle when the automatic stop detector detects the stop of the vehicle; and an automatic start device (18, SB10, SB18, SB24, SB26) for terminating the automatic stop of the engine and starting the engine when the automatic stop detector detects the automatic stop, when the clutch detector detects the depression of the clutch pedal, when the stop history checker does not find a history of stops, and when the accelerator detector detects depression of the accelerator pedal.
According to the present invention, when the automatic stop detector detects the automatic stop, when the clutch detector detects the depression of the clutch pedal, and when the stop history checker finds no stop history, that is, when the driver allows the vehicle to travel by inertia, the automatic stop state terminates, and the engine is restarted. Therefore, when the driver releases the clutch pedal, the driving force is provided, and thus the drivability can be improved.
Further, the automatic stop detector detects a fuel supply cut when the vehicle decelerates, to detect the automatic stop of the engine.
Because the automatic stop of the engine is detected based on the fuel supply cut when the vehicle decelerates, the drivability can be improved also in a vehicle which does not supply the fuel when the engine is stopped.